Ample clinical evidence has indicated that visual information processing plays en essential role in the sensorimotor integration during gait, although the underlying neural mechanisms are scarcely understood. In the recent three years, we have shown that neural system being composed of the lateral premotor-parietal cortex and cerebellum participates in visuomotor integration in gait and relates to the development of paradoxical movement in Parkinson's disease.Using single photon emission computed tomography (SPECT), we investigated regional cerebral blood flow changes (rCBF) induced by station, gait and visually guided gait in patients with Parkinson's disease and age-matched control subjects. Task-related rCBF images were obtained by injecting ィイD199mィエD1Tc radiotracers during the task performance. Task-related brain activation was determined by statistical parametric mapping. Station-related activation in elderly subjects was observed in the supplementary motor area (SMA), foot prima
… Morery motor areas (foot M1), visual cortex, and cerebellar vermis. During gait on a treadmill, elderly subjects showed activation in large mediodorsal frontoparietal areas including SMA and foot M1, visual cortex, dorsal brainstem and cerebellum. In parkinsonian patients, gait-related activation was reduced in the rostral SMA and cerebellar hemisphere, compared with the controls. During gait under visual guidance that improved parkinsonian gait, parkinsonian patients showed enhanced activation in the lateral premotor-parietal cortex and cerebellum. The findings suggest that the lateral premotor cortex, relatively well preserved in function in parkinsonian patients, may undertake the impaired SMA function in gait under the special condition.Using magnetoencephalograpy (MEG), we examined temporal characteristics of visual evoked signals during motor or nonmotor tasks. The simple visual evoked magnetic responses in the frontal lobe were enhanced in the attention-requiring conditions, suggesting the context-dependent modulation of the frontal visual response. Less